Various types of a point positioning apparatus and method which estimate the point position utilizing the satellite signals of positioning from the satellites are disclosed. A basic positioning estimation of these apparatus is to introduce a nonlinear simultaneous equation comprising of a code pseudorange, a receiver's position in three dimensions, and a clock error of a receiver. And this estimation applied a Newton method, an extended Kalmann Filter to the nonlinear simultaneous equation. Applying to this estimation, various types of a method to eliminate an influence of an ionosphere and a troposphere are disclosed, too. One method set the delay of the ionosphere and the delay of the troposphere to “0” at initial condition. And the other method estimated these delay utilizing a phase difference, including single phase difference.
The Geodetic Society of Japan, [Shinteiban GPS—jinkoueisei niyoru seimitsusokuisisutemu—(in Japanese), A new edition GPS—A precise positioning system—], JAPAN ASSOCIATION OF SURVEYORS, Nov. 15, 1989, p. 121-140